Manufacturing method

ABSTRACT

The present invention provides an assembly system employing at least a robotic or automated assembly apparatus to manipulate the components to be assembled and at least a first vision alignment system to align the components prior to their assembly. An adhesive dispense system is provided to connect, attach or otherwise adhere the components together. In a method in accord with the present invention for assembling components, a source of the components is provided is located relative to a global reference system. The components held by the source are then located relative to the global reference system based upon the determined location of the source. An adhesive is dispensed onto a first of the components and a second component is manipulated into an initial attachment position relative to the first component. The components are imaged by a local imaging system to establish their position relative to each other and the second component is moved into a desired attachment position and then moved into engagement with the adhesive and the first component. The adhesive may then be at least partially cured if desired.

FIELD OF THE INVENTION

[0001] The present invention relates generally to robotic manufacturingand in particular to apparatus and method for attaching a flexiblecircuit to a suspension used in the read/write head gimbal assembly ofhard disk drives.

BACKGROUND OF THE PRESENT INVENTION

[0002] The hard disk drive is the device most predominantly used forlong term memory storage in modern computer systems. In overview, a harddisk drive comprises a disk that is rotated at high speeds. The disk hasa magnetic coating and selected areas of the coating can be magnetizedwith the application of a magnetic field. A “read/write” device,commonly called a head, is suspended above the disk and moved radially,that is, from the edge of the disk toward the center and back. Electriccurrent is provided to the head which creates and applies a magneticfield to the disk as the head moves. Selective areas of the disk arepreferentially magnetized as the magnetic field is applied to the disk.Each magnetized area consists of a north and south pole selectivelyoriented in one of two preferred directions. Magnetized areas having anorth pole pointing in one of the two direction are designated as a “0”and in the other direction as a “1.” In this way the binary language ofcomputers consisting of zeroes and ones is assembled and data andprograms, which comprise zeroes and ones in binary computer language,are stored on the hard disk.

[0003] The hard disk provides large amounts of storage capability atrelatively low cost. In addition, as the technology continually matures,the storage density per unit of cost, that is, the quantity of datastored per dollar, is continuously increasing, as is the reliability ofthe hard disk and its related components, (collectively called the harddisk drive, hard drive, or disk drive) and the rate at which data can betransferred to and from the disk. That is, advancing hard disktechnology is resulting in the storage of increasing amounts ofinformation at decreasing unit costs. Yet, in spite of the rapid advancein storage technology, the technology continues to face cost pressuresas competition in the marketplace intensifies and computer programs growin size.

[0004] An exploded view of a flex circuit/suspension assembly is shownin FIG. 6, which illustrates several components including a csuspensionA and a flex circuit B. It will be understood that the actual physicalstructures of these components may vary in configuration. Typically, thesuspension A will include a base plate C, a radius (spring region) D, aloadbeam E, and a gimbal F. At least one tooling aperture G may beincluded. The flex circuit B may include a base H, which may be asynthetic material such as a polyimide, that supports typically aplurality of electrical traces or leads I of the flex circuit. Inaddition, any of the surface features of the suspension A and the flexcircuit B, such as the loadpoint J of the suspension A or the cure holesK of the flex circuit B, can be designated an optical target or analignment target for use in the process of assembling the flex circuitand the suspension to each other. Additionally, the suspension A and/orflex circuit B may include fiducials that are specifically placedthereon for imaging purposes during an assembly operation.

[0005] The components shown in FIG. 6 as well as all those associatedwith hard disk drives are small and continually decreasing in size.Consequently, any tolerance for misalignment of the components duringthe assembly process is also continuously decreasing while theirsusceptibility to damage during assembly is increasing.

[0006] Current disk drive assembly includes expensive, labor intensiveprocesses, particularly the assembly of the flex circuit to thesuspension assembly. The labor intensive nature of the assembly processhas several consequences. First, the labor increases the final cost ofthe assembled suspension. Second, because of the heavy use of labor inthe assembly, there is a meaningful quantity of handling of thecomponents by the assembler, which increases the likelihood of damage tothe components. Third, the assemblers are limited in both the precisionand speed with which the flex circuits can be assembled to thesuspensions. Fourth, even though human assemblers are used, the assemblyprocess is quite tooling intensive. Finally, as the part geometrieschange as the technology advances, the costs also increase because ofthe need for new tooling in the assembly of the new parts; that is, thetooling used is either not adaptable or not readily adaptable to newpart geometries.

[0007] Additional costs that are not included in calculation of the costof the use of human assemblers are those of the consumer whose harddrive fails, perhaps due to damage to a component by a human assembler.Though data backups are always advised, such advice is often unheeded.When a hard drive fails the consumer may lose valuable data that iseither not easily replaced or is replaced only at some cost in terms oftime and effort, if not actual cash outlays.

[0008] Many of the foregoing deficiencies in the employment of humanassemblers could be reduced or eliminated with a precision automatedassembly apparatus and method for attaching flex circuits tosuspensions. Automated assembly machines and methods should result inlower costs, reduced component handling and possible damage, and havegreater flexibility to accommodate variations in component types,geometries and improved placement tolerances.

SUMMARY OF THE INVENTION

[0009] It is an object of the present invention to provide new andimproved apparatus and methods that are not subject to the foregoingdisadvantages.

[0010] It is another object of the present invention to provide anapparatus that can be used for the automated assembly of one or morecomponent parts of a read/write head gimbal assembly to each other.

[0011] It is still another object of the present invention to provide amethod for the assembly of one or more component parts of a read/writehead gimbal assembly to each other.

[0012] The foregoing objects of the present invention are provided by anassembly system employing at least a robotic or automated assemblyapparatus to manipulate the components to be assembled and at least afirst vision alignment system to align the components prior to theirassembly. An adhesive dispense system is provided to connect, attach orotherwise adhere the components together.

[0013] In a method in accord with the present invention, a plurality ofcomponent parts are assembled to each other. A source of the componentparts is provided and the source is located relative to a global orabsolute reference system. The components held by the source are thenlocated relative to the global reference system based upon thedetermined location of the source. An adhesive is dispensed onto a firstof the components. A second component is manipulated into an initialattachment position relative to the first position and the componentsare imaged by a second or local imaging system to establish theirposition relative to each other. The second component will bemanipulated relative to the first based upon their calculated relativepositions to position the second component at the desired attachmentposition and then will be lowered into engagement with the adhesive andthe first component. The adhesive may then be at least partially curedif desired.

[0014] The foregoing objects of the invention will become apparent tothose skilled in the art when the following detailed description of theinvention is read in conjunction with the accompanying drawings andclaims. Throughout the drawings, like numerals refer to similar oridentical parts.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 illustrates an apparatus in accord with the presentinvention in a perspective overview.

[0016]FIG. 2 shows the manipulator arm of FIG. 1 in a front elevationview.

[0017]FIG. 3 depicts the manipulator arm of FIG. 1 in a side elevationview.

[0018]FIG. 4 illustrates the light source of FIGS. 1-4 in a top planview.

[0019]FIG. 5 is a process flow chart of a method in accord with thepresent invention.

[0020]FIG. 6 illustrates a flex circuit/suspension of the type that canbe assembled with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0021] An assembly apparatus 10 in accord with the present invention isshown in the Figures. Referring to FIG. 1, apparatus 10 includes a cover12, shown in phantom, and a cabinet 14. Cover 12 may be hingeablyattached to the cabinet 14. Cabinet 14 supplies the support structurefor the assembly apparatus to be described in greater detail hereafter.Cabinet 14 may include a table 16 that supports a plurality of componenttrays 16 and 18 at predetermined locations. Trays 16 and trays 18 holdcomponents to be attached or otherwise connected to each other, forexample, flex circuits and suspensions. Cabinet 14 also supports an xyzand θ robot 20 that is controlled by an appropriately programmedcomputer 22 or other appropriate device over a line 24. Robot 20 iscapable of manipulating parts in an orthogonal xyz coordinate systemrotationally about the z axis, thus providing manipulation in the θangular direction.

[0022] It will be understood by those in the art that both trays 16 and18 could be placed in any desired arrangement relative to robot 20 andthat the components contained therein could also be arranged as desiredwithin the trays. In any event computer 22 will be programmed with thenecessary information as to the relative locations of the trays and thecomponents therein.

[0023] The particular robotic system or apparatus 20 shown in the Figureis of the type presently manufactured by Zmation, Inc. of Portland,Oreg., and additional details concerning its construction and operationcan be obtained from the manufacturer. Other manufacturers of similarrobotic apparatus include Anorad Corporation of Hauppage, N.Y.

[0024] Robot 20 is movable in a plurality of rectangular coordinate axesand in at least one angular or rotational degree of freedom, as will bedescribed hereafter. In addition, as is known in robotic assemblyequipment, robot 20, could, if desired, include the ability tomanipulate components in additional degrees of freedom, that isangularly.

[0025] Robot 20 includes a pair of horizontal rails 26, 28 eachsupported by a pair of posts 30, 32, respectively. A transverse rail 34is movable along rails 26 and 28 in the direction indicated bydouble-headed arrow 36. Thus, rail 34 is movable in the X direction oralong the X axis and is sometimes referred to in the art as the X stage.

[0026] Rail 34 supports a manipulator arm 38 that is transverselymovable relative to the rails 26 and 28 along transverse rail 34 in thedirection indicated by double headed arrow 40. Thus, arm 38 is movablein the Y direction or along the Y axis and is sometimes referred to inthe art as the Y stage.

[0027] In addition, portions of the manipulator arm 38 will also bemovable in the direction of double headed arrow 42. This is the Zdirection or Z axis. Portions of the arm 38 are also movable in anangular direction as shown by double headed arrow 44.

[0028] Collectively, it will be understood that arrows 36, 40, and 42define a rectangular or xyz axis coordinate system and that themanipulator arm portions to be described hereafter are rotatable aboutthe Z axis as noted earlier.

[0029] Various devices are known in the art for providing movement in arobot system such as that illustrated here. For example, movement alongeach axis could be provided by an appropriate device for providinglinear motion, such as linear servo motors or other linear actuatormechanisms, such as ball screw or stepper motors, for example. In thepreferred embodiment, motion in the vertical or upright direction willbe provided by a linear voice coil motor with voltage feedback.

[0030] To provide the ability to control the robot 20 and position itwhere desired for the assembly operations, each motion providing devicewill include the appropriate position feedback system for providingposition information to the controller or computer 22. Movement in theangular or θ direction can be provided by a rotary servo motor with anencoder providing he desired feedback. As with the movement in therectangular coordinate system, the angular movement could be providedwith alternative devices including any other known type of rotaryactuated stage mechanism capable of providing the desired motion at thedesired accuracy. Once again, the rotary motion mechanism will providecontroller or computer 22 with the appropriate position information.

[0031] Manipulator arm 38 includes as shown a load support portion 46and an upright portion 48 elongated in the upright direction, thoughthis configuration is not critical to the present invention. Portions 46and 48 provide a support for the tools and instruments used to attachthe components to be assembled to each other. These tools andinstruments include a global vision system, an adhesive dispense system,a vacuum collet, an adhesive tack system, and a local vision system,each to be described in greater detail hereafter.

[0032] Referring now to FIGS. 2-4, the manipulator arm 38 will bedescribed in additional detail. Arm 38 includes a global vision imagingsystem (GVS) 50 that includes in a preferred embodiment a charged coupledevice (CCD), camera, a lighting system, and the appropriate lens andpositioning algorithms. GVS 50 is useful for globally or grosslypositioning the arm 38 relative to each of the trays 16 and 18. The GVS50 will also determine the position of the trays 16 and 18 relative toan absolute coordinate system defined by the position feedback systemsused with the XY stages. A particular advantage of using the GVS 50 isthat precise positioning of the component trays 16 and 18 within theapparatus 10 is not required. In addition, the GVS 50 will take intoaccount any variations in the manufacturing tolerances of the componenttrays 16 and 18. That is, even assuming that the trays 16 and 18 wereprecisely positioned relative to the apparatus 10, manufacturingtolerances in the trays 16 and 18 could result in the actual componentsbeing located at differing locations. These position differences in thecomponent locations are thus accounted for by the GVS 50.

[0033] Also included is a local vision system (LVS) 52. As with the GVS50, LVS 52 may include a CCD camera, a lens system, a lighting system,and vision processing tools/algorithms used by the appropriatecontroller or computer 22 to aid in the precision positioning of the arm38. The CCD camera is preferably mounted to the arm 38 so as to bemovable in the X and Y directions. Where the GVS 50 was used to grosslyposition the arm 38 relative to the component trays and thus theabsolute coordinate system defined by the position feedback system, theLVS is provided for locating the arm 38 relative to actual components tobe assembled to each other. Thus, the LVS 52 can be operated to imagethe components, such as a flex circuit and a suspension. These imagescan then be used by the computer 22 or other controller as desired, eachsupplied with the appropriate vision processing software, to control themovement of the robot 20 in the X, Y and θ stages. In this way then, therobot 20 can be precisely positioned with respect to first onecomponent, such as a flex circuit, and then relative to a second (orthird or more components if multiple components are being assembled toeach other) in order to assemble the components to each other.Preferably, the absolute position relative to the global coordinatesystem will not be used to precisely position the arm 38 relative to thecomponents. Rather, the position of the components themselves relativeto each other will provide the position information used for theprecision alignment of the components relative to each other.

[0034] FIGS. 2-3 further illustrate a component manipulation system. Thepresent invention contemplates the use of a vacuum system to pick up andmove the components for assembly. The present invention utilizes avacuum collet 54 mounted for movement along all four stages, that is theX, Y, Z, and θ stages. The use of vacuum component manipulation systemsfor robotic assembly are well known and will not be expounded upon here.Suffice it to say that such systems utilize a precisely configured toolhead that is maneuvered into position relative to a component, the toolhead is carefully applied to the component and a vacuum applied to thetool head. In this way, the component is held to the tool head by thedifferential air pressure between the atmosphere and the vacuum insidethe tool head. The tool head is then maneuvered along with the componentto the next stage in the assembly process. In the present invention, thevacuum collet 54 will be used to first pick up a flex circuit fromeither tray 16 or 18, depending upon the programming of the apparatus10. The pick up of the flex circuit will be accomplished by the movementof arm 38 using first the X and Y stages to position the arm 38 abovethe flex circuit and using the Z and θ stages to lower the vacuum colletshaft (not shown) and the attached collet 54 such that the collet 54 isin position to apply the vacuum. The vacuum collet will then be moved toa position above and relative to the suspension to which it will bebonded using the X, and/or Y and/or θ stages. The LVS will then be usedto position the flex circuit precisely relative to the suspension usingthe X and/or Y and/or Z and/or θ stages. The parts will then be attachedor otherwise fastened to each other. Where the apparatus 10 is providedwith the ability to identify damaged or defective parts, the vacuumcollet 54 may be used for additional tasks such as removing such partsfrom the trays 16 and 18.

[0035] Also shown in the Figures is an adhesive dispense system 56. Theadhesive dispense system 56 will include at least one adhesivedispensing unit, such as unit 58 as shown in the Figure, mounted to themanipulator arm portion 48. Unit 58 includes a syringe or other adhesivereservoir 60 as well as a dispensing tip or needle 62. The reservoir 60will be connected to the tip 62 via a hose or other conduit or channel64. The unit 58 will be movable preferably in the X and Y directionusing the X and Y Stages, as well as in the Z direction. In thepreferred embodiment of the present invention, such Z movement will beaccomplished with a separate actuator such as a pneumatic cylinder 66.In the preferred embodiment, the adhesive dispense units 58 may comprisea needle valve 67, which includes a valve movable in the Z direction fordispensing of the adhesive. Alternatively, they can also comprise spoolvalves, time-pressure valves, positive displacement valves, auger valvesor any other type of adhesive dispensing mechanism.

[0036] The present invention further includes an improved lightingsystem for illumination of the various components to provide a moreeffective imaging of the component parts, particularly when using LVS52. Referring now to FIGS. 2-4, the improved lighting system 68 will bedescribed. The lighting system 68 includes at least one and preferably aplurality of illumination sources 70. Preferably, a single light sourceis used to provide illumination to a bifurcated optical fiber so as toprovide uniform, nearly equal illumination from at least two directionsto reduce shadowing. Sources 70 direct their light onto a diffuser 72.To provide the high quality illumination needed to illuminate the traysand the components, the light from the source 70 should preferably bedirected at an angle of 15°, and within the range of 0° to 30° withrespect to the diffuser surface 74, which should be substantiallyplanar. Additionally, the light exit 76 from source 70 should bedisposed at a distance within the range of about 5 to about 40 mm.

[0037] The present invention further includes an ultraviolet or UV tacksystem for at least partially curing the adhesive applied by adhesivedispense unit 58. The UV tack system 78, which includes an ultravioletlight source, provides a “quick tack” of the components to each other,here the flex circuit to the suspension, after application of theadhesive and attachment of the component parts one to the other. Thequick tack provided by the system 78 substantially prevents the damagingloss of the precision positioning achieved by the combined operation ofthe vision systems and the manipulator arm 38, thus assuring that therelative placement of the components (the flex circuit relative to thesuspension, for example) does not change before the adhesive is fullycured in a curing oven later in the assembly process. Dependent upon anumber of factors, such as but not limited to the specific adhesivebeing used and the component geometry, the UV quick tack step may or maynot be required.

[0038] Having previously described an apparatus useful in accord withthe present invention, a method of assembling component parts in accordwith the present invention will now be described. Referring to FIG. 5,then, a flow chart illustrates a method 100 for assembling componentparts together. Thus, as seen in the figure, method 100 includes thestep 102 of loading trays, such as trays 16 and 18, into the apparatus10. The trays 16 and 18 will be pre-loaded with the components,indicated by the “A” and “B” in step 102, to be assembled together.

[0039] The use of pre-loaded trays has several advantages over the priorart assembly using human operators. First and foremost is that thehandling of the components by human operators is eliminated. This caneliminate several possible sources of component failure, including, butnot limited to, damage directly caused by the handling of the componentby the human operator, contamination of the components, and damagecaused by electrostatic discharge. In a preferred embodiment of thepresent invention, the trays would typically include the requisitenumbers of components such that new trays would be installed andcompleted trays would be removed at the same time to reduce the downtime on the apparatus 10. The trays could be loaded by operators orautomated load stations. Preferably, the apparatus 10 will includeapparatus for clamping or otherwise securing of the trays such that thetrays can not be located in the incorrect orientation or location. Thismay be accomplished by a vacuum or mechanical clamp. The employment ofthe trays or some other similar apparatus to “rough position” thecomponents reduces the amount of handling, the need for other toolingcurrently used in the manual assembly of such devices, and the use ofthe global vision system to more precisely align the parts prior toassembly.

[0040] Following loading of the trays, the apparatus 10 will then, if ithas not already done so, establish the global coordinate system (GBS) asat 104 as determined by the data provided by the position feedbackmechanisms of the X and Y stages. Once the global coordinate has beenestablished, it may be used to precisely locate the trays relativethereto.

[0041] The establishment of the GBS is accomplished in the preferredembodiment through the use of glass scale encoders attached to thelinear servos that serve as actuators for the X and Y stages. Thoseskilled in the art will recognize that the use of such informationenables the apparatus 10 to establish a coordinate system with an origindefined accordingly and to provide for the movement of the manipulatorarm 38 to precise points (x,y) as determined relative to the origin(0,0) located according to the established GBS. For example, the arm 38could be moved to a point (38, 88) which would be 38 units in thepositive x direction and 88 units in the positive y direction. The unitsof movement could be units of length or encoder units or whatever unitis selected for use.

[0042] After the component trays have been loaded into the apparatus 10,the GVS along with the arm 38 will be moved to predefined orpredetermined initial locations relative to the GBS. The predefinedinitial position is located so as to position the GVS relatively nearthe trays 16 and 18 such that it is able to image and locate apredetermined number, preferably two, of optical targets or fiducialslocated thereon. By determining the location of the fiducials thelocation of the trays can be determined. To determine the position ofthe fiducials relative to the GBS, the GVS will image the fiducials andthen use vision processing tools and/or algorithms to precisely locatethe fiducials. Thus, locating the fiducials will determine the traypositions relative to the X, Y, and θ directions. Knowing the traylocations in turn locates the positions of the components within thetrays since the locations of the components within the tray relative tothe fiducials will also be known. Thus, the component cavities holdingcomponents such as flex circuits and suspensions, will now be locatedand labeled as to their respective row number and column number in theirrespective trays, and each of these (row, column) labels will have aprecise X and Y (X,Y) coordinate associated with it. That is, each traymay include cavities or receptacles of a predetermined configurationwhere the components reside. Locating the trays relative to the GBS withthe GVS will thus locate the cavities or receptacles and, therefore, thecomponents.

[0043] Once the GVS has isolated each component part as to its locationrelative to the GBS, the parts can be bonded to each other. In summary,the adhesive will be dispensed onto one part, the second part will bepicked up and placed on the first part, the UV quick tack will beapplied to tack the parts together, and the process will be repeated.

[0044] In greater detail, the manipulator arm 38 will be moved in the Xand Y directions to position the adhesive dispense unit 56 above thecomponent, such as a suspension. The z actuator 66 for the needle tip 62will be actuated to lower the needle tip to the proper height above thecomponent for the dispensing of the adhesive and the adhesive will bedispensed as indicated at 106 using the needle valve 67 in a controlledvolume at a controlled rate and in a controlled pattern, all of whichmay vary according to geometry and specifications of the particularcomponents being assembled.

[0045] Preferably, the LVS is not used during the adhesive dispense stepand the adhesive is dispensed based upon the location of the cavity asdetermined by the GVS. The LVS can be used if desired to position theneedle tip 62 at the desired location, but doing so will result in anincrease in the cycle time, and the time to complete an assembly.

[0046] Following the dispensing of the adhesive, the component to bebonded to the first component will be picked up by the vacuum collet 54as at 108 where it is indicated that the collet picks component A. Toaccomplish this arm 38 will be moved over to the other component tray,such as the flex circuit tray, and the vacuum collet 54 will bepositioned over the component to be bonded to the component in the firsttray. The Z stage actuator will then lower the collet 54 as determinedby the feedback system associated with the actuator steps with aprecise, predetermined force relative to the component, coming intosufficient contact with the component such that upon engaging the vacuumthe component will be held by the differential air pressure to thecollet. The Z stage actuator will be actuated again and the collet andattached component will be lifted or picked up. The picking up of thesecond component can be a “blind pick” based upon the calculatedposition of the component to be picked up, or one of the vision systemscan be used to precisely position the collet in the X, Y, and θdirections relative to the component. Once again, to reduce assemblycycle time it is preferred that the pick be a blind pick.

[0047] The arm 38 then moves to position the picked component “A” overthe component “B” as indicated at 110. As an example of this step, thearm 38 is moved so as to position the collet 54 holding the flex circuitover the suspension upon which adhesive has been dispensed. While thismay be the same component upon which adhesive has just been dispensed,it need not necessarily be the case. For example, it may be desirous toallow the adhesive to cure for a predetermined period of time before theparts are bonded to each other, in which case, a second component couldbe bonded to a first component after some period of cure time. Forexample, processing could begin with application of adhesive to aplurality of components and then the alternating process of adhesiveapplication and part bonding could be conducted, with the secondcomponent being bonded to the first component having adhesive appliedfor the longest time.

[0048] After the collet 54 is moved over the component with the adhesiveapplied to it, both components will be within the field of view, showngenerally and not to scale as dotted line circles FOV in FIG. 6 by wayof illustration only, of the LVS 52 and within the same depth of focus.The LVS will image the components, and using fiducials or opticaltargets on the component parts will determine their position relative toeach other using vison tools and or software processing algorithms. Inaddition, both components will be within the same depth of focus, whichthereby enables the LVS and GVS cameras to stay fixed relative to eachother. Because the LVS is fixed relative to the collet, mechanicalerrors arising from camera movement are not introduced into thecalculation of the relative component positions. Once the preciserelative positions are identified, the collet 38 will be positionedusing the X, Y, and θ stages to align the first and second componentsfor bonding. This positioning may be done using a single image capture,position calculation, and movement of the arm 38, or it may be repeaptedseveral times to achieve the desired placement accuracy. The number ofiterations of imaging, calculation, and movement can be dependant onsuch factors as stage quality, that is, movement precision,specifications required, vibration in the production plant, etc. Therelative component position determination can be accomplished indifferent ways according to several known several methods; generally,the relative positions will be calculated using algebra and trigonometryin combination with the precise dimensions of the components, which willhave previously been entered into the computer on a part specific basis.

[0049] In some assembly procedures, the step of aligning the componentparts may focus on alignment of the fiducials or optical targets. Inother assembly procedures, computer 22 may have been programmed with thelocations of alignment targets out of the field of view of the LVS. Inthis latter situation, the alignment of those out of view alignmenttargets will be made by calculating the relative locations of thosealignment targets using information concerning the parts previouslyprogrammed into the computer 22.

[0050] Preferably, the present method utilizes a small field of view inthe LVS to increase the accuracy and precision of the procedure. Thatis, in a preferred embodiment a field of view of 2 mm by 2 mm in size isutilized. Preferably, using presently available optical equipment thefield of view will be less than about 4 mm by about 4 mm. The smallfield of view also enables the items of interest to be zoomed in on asdesired. The small field of view, however, means that the desiredalignment targets may not be within the field of view, however, therebyrequiring an alignment calculation to be made as just described above.

[0051] Once the proper relative position is achieved, the collet 54 willbe lowered along with the component using the Z stage actuator into abonding engagement with the first component as at 112. That is, the Zstage actuator will lower the collet 54 and the flex circuit with aknown z-force to provide a precisely located, controlled placement thatreduces the chance of misaligned components as well as the damage froman uncontrolled or lesser controlled application of force between theparts by the human operator. The UV tack can be activated at 114 toprovide a quick cure or tack of the adhesive. The vacuum will bereleased then from the collet such that the component is no longer heldby the collet 54 and the collet will be raised by the Z stage actuatoras at 116. The cycle will then be repeated with the dispensing ofadhesive at 106 onto another component. The cycle just described willalso be repeated until each of the components in the tray have beenaddressed by the controller or computer 22. The trays can then beremoved and new trays filled with components placed within the apparatus10 for assembly.

[0052] Application of the vision systems in the present inventionprovides superior capabilities in terms of placement or positioning ofthe components compared to existing manual methods which are dependentupon on the precision—or lack thereof—of human eyes and/or fixed/hardtooling alignment mechanisms. Use of the vision systems also providessuperior flexibility. That is, when a new part geometry is used with thepresent invention, very few changes will need to be made to the presentinvention. For example, the principal changes will occur in thesoftware, though different trays and a new vacuum collet may be neededto conform to the new part geometry. In contrast, when part geometrieschange at present, new tools must be constructed to accommodate thedifferent geometries.

[0053] The vision systems can also be used to inspect for and identifydefective components and when found, to dispose of them before they arebonded to a non-defective component and ultimately delivered to aconsumer. The automated nature of the process also facilitates thecollection and storage of operational data that can be used to monitorthe operation of the system, the number of defective components, theprecision of the alignment, and other information as specified anddesired.

[0054] In some embodiments of the present invention, the two componentsmay need to be “interleaved” to complete the assembly. For example, inaddition to the flex circuit being lowered to the suspension, the Xand/or Y and/or θ stage would also be used to lower and mesh orinterleave the flex circuit with the suspension sequentially orsimultaneously.

[0055] In other embodiments of the present invention, the electricalleads on the flex circuit may need to be bent to a certain geometrybefore and/or after the bonding process to the suspension. This is alsosomething that the flexible process described herein allows for. Thebending of the electrical leads could be accomplished by the addition ofanother tool on the arm 38, or possibly by the collet 54 itself. Instill further embodiments, the method of transporting the componentsthrough the process described may be a conveyor type system. In stillanother embodiment of the present invention the suspension could bebrought to the flex circuit rather than bringing the flex circuit to thesuspension as hereinbefore described.

[0056] As shown, rail 34 is disposed above rails 26 and 28, though as isknown in the art, this relative position is not critical to thefunctioning of such robots. Thus, rail 34 could be disposed below or atan elevation substantially equal to rails 26 or 28.

[0057] While a specific robotic assembly apparatus 20 has been describedabove, it will be understood and appreciated by those skilled in the artthat other robotic systems capable of performing the aforementionedmotions and functions could be used in lieu of the described apparatus20 with equal facility.

[0058] The present invention having thus been described, othermodifications, alterations, or substitutions may now suggest themselvesto those skilled in the art, all of which are within the spirit andscope of the present invention. It is therefore intended that thepresent invention be limited only by the scope of the attached claimsbelow.

What is claimed is:
 1. A method for assembling a plurality of componentsto each other, said method comprising: determining an absolute referencesystem; providing at least one source for a plurality of components;determining the location of the at least one source relative to theabsolute reference system; determining the locations of the componentsrelative to the source; dispensing an adhesive onto a first of thecomponents; and disposing a second of the components into an adheringposition relative to the first component.
 2. The method of claim 1 andfurther including: determining the location of the second componentrelative to the first component.
 3. The method of claim 2 and furtherincluding: curing the adhesive at least partially.
 4. The method ofclaim 3 wherein said curing step includes: exposing the adhesive to anultraviolet light source.
 5. The method of claim 1 and furtherincluding: curing the adhesive at least partially.
 6. The method ofclaim 5 wherein said curing step includes: exposing the adhesive to anultraviolet light source.
 7. The method of claim 1 wherein the firstcomponent is a flex circuit.
 8. The method of claim 7 wherein the firstcomponent is a suspension.
 9. The method of claim 1 wherein the firstcomponent is a suspension.
 10. The method of claim 1 wherein the sourceincludes optical targets and further including: determining the locationof the optical targets relative to the absolute reference system. 11.The method of claim 1 wherein said step of determining the location ofthe at least one source comprises: imaging the at least one source witha first camera.
 12. The method of claim 11 and further including:disposing the source at a predetermined source location; and disposingthe first camera at a predetermined initial position for imaging the atleast one source.
 13. The method of claim 1 wherein the source comprisesat least one tray holding the components.
 14. The method of claim 1determining the relative positions of the two components to be assembledto each other, said determining step including imaging the twocomponents simultaneously with a camera.
 15. The method of claim 14wherein the source includes optical targets and further including:determining the location of the optical targets relative to the absolutereference system, said step of determining the location of the opticaltargets including imaging the at least one source with a camera.
 16. Themethod of claim 15 and further including: curing the adhesive at leastpartially.
 17. The method of claim 16 wherein said curing step includes:exposing the adhesive to an ultraviolet light source.
 18. The method ofclaim 15 wherein said step of disposing a second of the components intoan adhering position relative to the first component comprises:determining a preferred relative position of the second componentrelative to the first component; picking up the second component andmoving it into an initial position relative to the first component;calculating the relative positions of the first and second componentsbased upon the step of imaging the components; and moving the secondcomponent to a new position closer to the preferred relative position.19. The method of claim 18 and further including: curing the adhesive atleast partially.
 20. The method of claim 19 wherein said curing stepincludes: exposing the adhesive to an ultraviolet light source.
 21. Themethod of claiml4 wherein the two components are aligned for attachmentcalculating the relative positions of alignment targets on thecomponents that are out of the field of view of the cameras.
 22. Themethod of claim 21 wherein the source includes optical targets andfurther including: determining the location of the optical targetsrelative to the absolute reference system, said step of determining thelocation of the optical targets including imaging the at least onesource with a camera.
 23. The method of claim 22 and further including:curing the adhesive at least partially.
 24. The method of claim 22wherein said step of disposing a second of the components into anadhering position relative to the first component comprises: determininga preferred relative position of the second component relative to thefirst component; picking up the second component and moving it into aninitial position relative to the first component; calculating therelative positions of the first and second components based upon thestep of imaging the components; and moving the second component to a newposition closer to the preferred relative position such that saidalignment targets are properly aligned for attachment of the componentsto each other.
 25. The method of claim 1 and determining the relativepositions of the two components to be assembled to each other, saiddetermining step including: providing a camera for imaging the twocomponents; disposing the two components such that said components arewithin the field of view of the camera and at the same relative depth offocus; and imaging the two components with the camera.
 26. The method ofclaim 25 wherein said field of view is less than about 4 mm by 4 mm. 27.The method of claim 25 wherein the two components are aligned forattachment calculating the relative positions of alignment targets onthe components that are out of the field of view of the cameras.
 28. Themethod of claim 27 wherein said step of disposing a second of thecomponents into an adhering position relative to the first componentcomprises: determining a preferred relative position of the secondcomponent relative to the first component; picking up the secondcomponent and moving it into an initial position relative to the firstcomponent; calculating the relative positions of the first and secondcomponents based upon the step of imaging the components; and moving thesecond component to a new position closer to the preferred relativeposition such that said alignment targets are properly aligned forattachment of the components to each other.
 29. The method of claim 28wherein said field of view is less than about 4 mm by 4 mm.
 30. Anapparatus for assembling at least a first component to a secondcomponent, said apparatus comprising: a robotic assembly apparatusincluding a manipulator arm movable in xyz and θ directions; a globalvision system comprising a camera, said global vision system beingprovided for locating the first component relative to a global referencesystem; a vacuum collet attached to said manipulator arm formanipulating at least one of the components and placing it in anattachment position relative to the other component wherein thecomponents are disposed substantially one above the other; an adhesivedispense system attached to said manipulator arm for dispensing adhesiveonto at least a selected one of said components; and a local visionsystem attached to said manipulator arm, said local vision system beingprovided for imaging both components when said components are in saidattachment position.
 31. The apparatus of claim 30 wherein said localvision system includes a local vision lighting system, said local visionlighting system comprising: a diffuser plate; and a pair of lightsources directed at said diffuser plate.
 32. The apparatus of claim 31wherein said light sources are directed at said diffuser plate fromsubstantially opposite directions.
 33. The apparatus of claim 32 whereinsaid diffuser plate has a substantially planar surface and said lightsources direct light at said diffuser surface at an angle in the rangeof about 0° to about 30° with respect to said diffuser surface.
 34. Theapparatus of claim 33 wherein said light sources direct light at saiddiffuser surface at an angle of about 15° with respect to said diffusersurface.
 35. The apparatus of claim 33 wherein said light sources aredisposed at a distance from said diffuser surface within a range ofabout 5 to about 40 mm.
 36. The apparatus of claim 31 wherein saiddiffuser plate has a substantially planar surface and said light sourcesdirect light at said diffuser surface at an angle in the range of about0° to about 30° with respect to said diffuser surface.
 37. The apparatusof claim 36 wherein said light sources direct light at said diffusersurface at an angle of about 15° with respect to said diffuser surface.38. The apparatus of claim 36 wherein said light sources are disposed ata distance from said diffuser surface within a range of about 5 to about40 mm.
 39. The apparatus of claim 30 and further including means for atleast partially curing dispensed adhesive.
 40. The apparatus of claim 39wherein said means for at least partially curing comprises anultraviolet light source.